Abstract:

To describe the mechanical behavior of NEPE propellant under finite deformation condition，a viscohyperelastic constitutive equation was proposed. The equation comprises two parts—a component based on Yeoh strain energy function to characterize the static hyperelastic behaviour, and another to define nonlinear viscoelastic behaviour. The tensile test and relaxation test were employed to determine the parameters in the constitutive relationship. The comparison between the predicted results based on the proposed model and the experimental results shows that it is able to aptly describe the viscohyperelastic behaviour of NEPE propellant.

Key words: ordnance science and technology, NEPE propellant, constitutive equation, viscohyperelastic, nonlinear